Mobile devices are becoming ever smaller, and mobile devices that are worn on a wrist are necessarily limited in size. Furthermore, given their small size much of the outer surface will be covered by a screen in order to allow the screen to have an acceptable size to display information. The electronic components of such devices will generally be contained within a main body portion beneath the screen and will generally be protected by a metal casing.
Traditionally wrist worn devices have simply indicated time and perhaps had some alarm function. With reducing size of electronic components it may be advantageous to provide wrist worn devices with additional functionality and perhaps with communication circuitry such that they can receive and transmit information. Such communication circuitry will need an antenna to output and receive the radiation, the size and type of the antenna being dependent on the wavelength of the radiation. Arranging such an antenna on a device of a constrained size that is worn by a user, such that only one face is outward looking, and that may additionally have a metal casing to protect electronic components is challenging.